There is a bubble tube measuring portion in which a bubble and liquid are sealed is provided in a container case, and the container case is configured so that the levelness or the perpendicularity of a measurement surface is measured based on the bubble position of the bubble tube measuring portion placed on a desired measurement surface. In such a water level, the bubble tube measuring portion is commonly provided to a mounting body made of resin, the mounting body is disposed inside the container case, and the mounting body is fixed in a prescribed position inside the container case so that the bubble tube measuring portion provided to the container case can be viewed from a window provided to the container case.
When the fixed orientation of the mounting body fixed inside the container case is dislocated, the bubble position of the bubble tube measuring portion provided to the mounting body becomes dislocated. Therefore, many proposals have been made for this type of level, wherein the mounting body inside the container case is adjusted by micromotion (adjusted by microrotation), and the fixed orientation of the mounting body is corrected, i.e., the bubble position of the bubble tube measuring portion is corrected.
In this manner, various configurations have been proposed in prior art as configurations in which the fixed orientation of the mounting body disposed in the container case is corrected in order to correct the bubble position, and a screw is commonly threadably disposed toward the mounting body fixed inside the container case from the exterior of the container case, the mounting body is adjusted by micromotion or microrotation by the amount of threading of the screw to correct the fixed orientation, i.e., to correct the bubble position.
Therefore, these configurations have practical problems in that the screw for correcting the fixed orientation of the mounting body disposed inside the container case and correcting the bubble position is threadably disposed toward the mounting body from the exterior of the container case, and the appearance is poor because the screw is provided in an exposed state in a position that can be seen from the exterior of the case. Also, there are cases in which a spring that is critical for determining the fixed orientation of the mounting body and determining the bubble position by the amount of threading comes into contact with an object, whereby the screw is inadvertently turned, and the fixed orientation of the mounting body and the bubble position become dislocated. In such cases, a cover or another structure must be provided in order to prevent the screw from being exposed.